Super strength eckies doing the rounds in NZ right now

The ecstasy going around New Zealand this festival season could be dangerously strong.

Writing for The Spinoff, Wendy Allison of drug testing organisation KnowYourStuffNZ says their testing has revealed pills containing two to three times the average dose of MDMA.

Ms Allison says, in the past, most people who took what they believed was ecstasy were actually not taking MDMA. In KnowYourStuffNZ's first year, just 20 percent of the drugs they tested actually contained MDMA.

Recently, however, ecstasy has tended to not only contain real MDMA, but even multiple doses.

"This season we've seen several pills weighing up to 580mg in which the main ingredient is MDMA, suggesting potentially two to three times the average dose," Ms Allison wrote.

She says this poses a health risk to drugtakers - while an average dose of MDMA is considered relatively safe, higher doses can cause something called 'serotonin syndrome', a potentially fatal condition that can dangerously overheat the body.

Ms Allison is calling for pill testing at events to be made "explicitly legal", as the practice's legality is currently something of a grey area.

"If the aim really is to reduce harm, the Government needs to acknowledge that people use drugs, end prohibition and the associated illicit markets, and create regulation that includes quality control and labelling, just as we have with legal drugs such as alcohol and coffee," she wrote.

The KnowYourStuffNZ website advises people to avoid certain pressed pills which have been estimated to contain larger than usual amounts of MDMA.

These include "green guccis" (rectangular green pill with the Gucci logo) and "yellow rolexes" (yellow pills shaped like the Rolex crown logo).

KnowYourStuffNZ also warns against taking "pink porsches", which are bright pink shield-shaped pills with the Porsche logo. They say users have reported unpleasant experiences after taking them, and that testing suggested they may contain "dangerous pharmaceutical agents" as well a high dose of MDMA.

Fifteen people were hospitalised after displaying norovirus-like symptoms at the Rhythm & Vines festival in December.

Police initially said they had been told that some of the festival-goers had taken ecstasy, although they later retracted the claim.